If you have a sudden increase of BOD by 50% or a BOD>400, what is this termed?

A sudden increase in Biological Oxygen Demand (BOD) is an indicator of increased organic load in the wastewater. BOD is a measure of the amount of oxygen that microorganisms will consume while decomposing organic matter under aerobic conditions. When there is a significant rise in BOD, particularly by 50% or exceeding a threshold of 400 mg/L, it signifies that there is a higher concentration of organic material present in the wastewater that requires treatment.

This increase in organic load is critical because it can impact the performance of the treatment processes. High organic loads can lead to oxygen depletion in the aeration tanks and can overload the microbial populations that are responsible for breaking down the organic matter. Therefore, the correct term for this scenario is increased organic load, as it directly correlates with the elevated levels of BOD observed.